53 Pa. Stat. § 881.307
Each single coverage member of the system created under this Article III, shall be required to contribute no more than eight per cent of his salary or compensation to the fund based on a uniform contribution rate as determined by the actuary to provide the benefit under this article.
The amount of contribution by each joint coverage member shall be computed in the manner described above for a single coverage member, except that the amount of such deductions from salary or compensation shall be reduced with respect to wages (as defined in the Federal Insurance Contributions Act) by forty per cent of the tax on employes prescribed by the Federal Insurance Contributions Act exclusive of that portion of such tax attributable to disability coverage.
Members' contributions shall be paid into the fund by the municipality through payroll deductions in such manner and at such time as the board may by rule and regulation determine.
53 P.S. § 881.307